Spironolactone differently influences remodeling of the left ventricle and aorta in L-NAME-induced hypertension

Area of Science:

• Cardiovascular Pharmacology
• Renal Physiology
• Molecular Cardiology

Background:

• Aldosterone receptor antagonists, like spironolactone, are known to prevent cardiac remodeling in left ventricular hypertrophy.
• Hypertension induced by N(G)-nitro-L-arginine methyl ester (L-NAME) is associated with reduced nitric oxide (NO) synthase activity, cardiac hypertrophy, and aortic remodeling.

Purpose of the Study:

• To investigate the efficacy of spironolactone in preventing hypertension, reduced NO synthase activity, and cardiac and aortic remodeling in a rat model of L-NAME-induced hypertension.

Main Methods:

• Four groups of rats were studied: control, spironolactone, L-NAME, and L-NAME + spironolactone.
• Animals were treated for 5 weeks, and NO synthase activity, blood pressure, cardiac hypertrophy (indicated by DNA concentration), and aortic remodeling were assessed.

Main Results:

• L-NAME induced hypertension, decreased NO synthase activity in the heart and kidneys, left ventricular hypertrophy (LVH), and aortic remodeling.
• Spironolactone treatment prevented the inhibition of NO synthase activity and partially attenuated hypertension and LVH.
• Spironolactone did not prevent the remodeling of the aorta.

Conclusions:

• Spironolactone enhances nitric oxide production and offers partial protection against hypertension and LVH in NO-deficient hypertension.
• The study suggests that cardiac and aortic growth in L-NAME-induced hypertension are regulated by distinct mechanisms.